Automatic winding device for strap fastener

ABSTRACT

An automatic winding device is provided for a strap fastener. The automatic winding device includes a housing, a reel rotationally received in the housing for winding a strap introduced through the strap fastener and a spring connected between the housing and the reel. A shaft is securely received in the housing for supporting the reel. The spring is a coil spring mounted on the shaft and received in the reel. The spring includes an internal end secured to the shaft and an external end secured to the reel. In an aspect, at least one ratchet wheel is formed on the reel, and a detent is movably mounted on the housing for releasable engagement with the reel. The detent is biased by means of a second spring. The housing defines a slot through which the detent is inserted. The housing includes a stem formed thereon within the slot. The detent includes a groove defined therein for receiving the stem and the second spring. Thus, the second spring is compressed between the stem and a portion of the detent.

BACKGROUND OF INVENTION

[0001] 1. Field of Invention

[0002] The present invention relates to a strap fastener and, more particularly, to an automatic winding device for a strap fastener.

[0003] 2. Related Prior Art

[0004] Referring to FIG. 6, a conventional strap fastener includes a base 91, an axis 93, a lever 96, a first detent 97, two ratchet wheels 98 and a second detent 99. The axis 93 is rotationally mounted on the base 91. The ratchet wheels 98 are securely mounted on the axis 93. The first detent 97 is mounted on the base 91 for engagement with the ratchet wheels 98 so that rotation of the axis 93 relative to the base 91 is allowed but rotation of the axis 83 in a second direction opposite to the first direction is avoided. The lever 96 is pivotally mounted on the axis 93. The second detent 99 is mounted on the lever 96 for engagement with the ratchet wheels 98 so that pivoting of the lever 96 in the first direction results in rotation of the axis 83 in the first direction but pivoting of the lever 96 in the second direction does not entail rotation of the axis in the second direction. A strap 92 is wound on the axis 93. The strap 92 is connected with a hook 94 at an end. When a section of the strap 92 is not used, a user has to roll this idle section of the strap 92 into a roll 95 by naked hands, i.e., not using any tool. It is troublesome and time-consuming to roll the idle section of the strap 92 into the roll 95. Moreover, it is troublesome to retain the idle section of the strap 92 in the roll 95.

[0005] The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.

SUMMARY OF INVENTION

[0006] It is the primary objective of the present invention to provide a strap fastener with an automatic winding device for automatically winding an idle section of a strap.

[0007] According to the present invention, an automatic winding device is provided for a strap fastener. The automatic winding device includes a housing, a reel rotationally received in the housing for winding a strap introduced through the strap fastener and a spring connected between the housing and the reel. A shaft is securely received in the housing for supporting the reel. The spring is a coil spring mounted on the shaft and received in the reel. The spring includes an internal end secured to the shaft and an external end secured to the reel.

[0008] In an aspect, at least one ratchet wheel is formed on the reel, and a detent is movably mounted on the housing for releasable engagement with the reel. The detent is biased by means of a second spring. The housing defines a slot through which the detent is inserted. The housing includes a stem formed thereon within the slot. The detent includes a groove defined therein for receiving the stem and the second spring. Thus, the second spring is compressed between the stem and a portion of the detent.

[0009] Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0010] The present invention will be described through detailed illustration of embodiments referring to the attached drawings.

[0011]FIG. 1 is a perspective view of a strap fastener equipped with an automatic winding device according to the present invention.

[0012]FIG. 2 is an exploded view of the strap fastener and the automatic winding device shown in FIG. 1.

[0013] FIGS. 3-5 are cross-sectional views of the strap fastener and the automatic winding device shown in FIG. 1.

[0014]FIG. 6 is a perspective view of a conventional strap fastener.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

[0015] Referring to FIGS. 1 and 2, a strap fastener 1 is equipped with an automatic winding device 2 according to the preferred embodiment of the present invention. The strap fastener 1 is conventional and reference is given to the Related Prior Art for details thereof. However, it is stated here that the strap fastener 1 includes an axis 11 in which a slot 12 is defined.

[0016] The automatic winding device 2 includes a housing 3, a reel 4 rotationally received in the housing 3, a spring 6 arranged between the housing 3 and the reel 4 and a detent 7 movably mounted on the housing 3 for engagement with the reel 4.

[0017] The housing 3 consists of two halves 31 that are separately formed and can be combined. Each of the halves 31 includes a space 32 defined therein, a first slot 34 defined therein and communicated with the space 32 and a second slot 35 defined therein and communicated with the space 32. A shaft 33 is integrated with or secured to one of the halves 31. A stem 36 is integrated with or secured to one of the halves 31 within the second slot 35. The shaft 33 defines two longitudinal slits 37 opposite to each other.

[0018] The reel 4 is hollow and therefore includes an internal face. A recess 41 is defined in the internal face of the reel 4. Two ratchet wheels 42 are formed on the reel 4.

[0019] The spring 6 is a coil spring that includes an internal end and an external end.

[0020] The detent 7 includes a slot or groove 72 defined in a side.

[0021] In assembly, the reel 4 is mounted on the shaft 33. The internal end of the spring 6 is received in the slits 37. The internal end of the spring 6 is received in the recess 41. Thus, the spring 6 is connected between the shaft 33 and the reel 4. The detent 7 is received in the slot 35 defined in one of the halves 31. A spring 71 is received in the slot or groove 72. A strap 5 is wound on the reel 4. The strap 5 is inserted through the slot 34 defined in the one of the halves 31. The strap 5 is inserted through the slot 12 defined in the axis 11 of the strap fastener 1. A hook 51 is secured to the free end of the strap 5. The halves 31 are combined with each other so as to form the housing 3 for shielding the shaft 3, the reel 4, the spring 6 and the strap 5. The stem 36 is inserted in the slot or groove 72. The spring 71 is compressed between the stem 36 and a portion of the detent 7 for biasing the detent 7 into engagement with the ratchet wheels 42. A strap 8 is connected with the housing 3 at an end and connected with a hook 81 at an opposite end.

[0022] Referring to FIG. 3, to use the strap fastener 1 and the automatic winding device 2, a user (not shown) hooks the hook 81 on a proper position. The user has to pull the strap 5 from the reel 4. Referring to FIG. 4, the detent 7 can be disengaged from the ratchet wheels 42 in order to allow rotation of the reel 4 on the shaft 33, thus producing a torque in the spring 6. The user hooks the hook 51 on a proper position. Finally, the user can operate the strap fastener 1 to tension and fasten the strap 5. As shown in FIG. 3, the engagement of the detent 7 with the ratchet wheels 42 avoids unintentional winding of the strap 5 onto the reel 4. Referring to FIG. 5, the user can disengage the detent 7 from the ratchet wheels 42 via pulling, thus allowing the spring 6 to rotate the reel 4 due to the torque, thus winding the strap 5 onto the reel 4.

[0023] The present invention has been described via illustration of the preferred embodiment. After a study of this specification, those skilled in the art can derive various variations from the preferred embodiment. Therefore, the preferred embodiment is only taken as an example and shall not limit the scope of the present invention that is defined in the claims. 

1. An automatic winding device for a strap fastener, the automatic winding device including a housing, a reel rotationally received in the housing for winding a strap introduced through the strap fastener and a spring connected between the housing and the reel.
 2. The automatic winding device according to claim 1 including a shaft securely received in the housing for supporting the reel.
 3. The automatic winding device according to claim 2 wherein the spring includes a first end secured to the shaft and a second end secured to the reel.
 4. The automatic winding device according to claim 3 wherein the shaft defines at least one slit for receiving the first end of the spring.
 5. The automatic winding device according to claim 3 wherein the reel defines a recess for receiving the second end of the spring.
 6. The automatic winding device according to claim 2 wherein the spring is a coil spring mounted on the shaft and received in the reel.
 7. The automatic winding device according to claim 6 wherein the spring includes an internal end secured to the shaft and an external end secured to the reel.
 8. The automatic winding device according to claim 7 wherein the shaft defines at least one slit for receiving the internal end of the spring.
 9. The automatic winding device according to claim 7 wherein the reel defines a recess in an internal face for receiving the external end of the spring.
 10. An automatic winding device for a strap fastener, the automatic winding device including a housing, a reel rotationally received in the housing for winding a strap introduced through the strap fastener, a spring connected between the housing and the reel, at least one ratchet wheel formed on the reel and a detent movably mounted on the housing for releasable engagement with the reel.
 11. The automatic winding device according to claim 10 wherein the housing defines a slot through the detent is inserted.
 12. The automatic winding device according to claim 11 including a second spring for biasing the detent into engagement with the at least one ratchet wheel.
 13. The automatic winding device according to claim 12 wherein the housing includes a stem formed thereon within the slot, and the detent includes a groove defined therein for receiving the stem and the second spring so that the second spring is compressed between the stem and a portion of the detent.
 14. The automatic winding device according to claim 10 wherein the housing defines a first slot through which the strap is inserted. 